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The recovery of rare-earth elements (REEs) from rare-earth blast furnace slag (RE-BFS) is crucial for advancing the circular economy. However, the development of related processes is significantly hindered by the severe lack of fundamental thermodynamic data on REE systems, underscoring the urgent need for detailed studies in this area. In the present work, the equilibrium phase relations of CaO-SiO2-CeO2-10.0 wt.% Al2O3-5.0 wt.% MgO system at 1300°C and 1400°C were experimentally carried out using the high-temperature equilibration-quenching technique followed by X-ray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS), as well as thermodynamic calculation. One liquidus region, a liquid–CeO2 two-phase coexisting region, and a liquid–CeO2–akermanite three-phase coexisting region were confirmed within the investigated composition ranges. Based on the experimental data and phase compositions, the phase diagram of the CaO-SiO2-CeO2-10.0 wt.% Al2O3-5.0 wt.% MgO system was constructed at 1300°C and 1400°C. There were great discrepancies between the experimental results and calculated results by FactSage 8.2. The phase equilibria data obtained from this study provide fundamental thermodynamic information for the development of innovative processes aimed at extracting REEs from RE-BFS, as well as enriching the existing REEs database. [ABSTRACT FROM AUTHOR]

Dodonea viscosa-zinc oxide (DV-ZnO) nanocomposite was synthesized and characterized using Fourier transform infrared (FTIR), thermal gravimetric method (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The most abundant compounds in the plant extract were explored using gas chromatography-mass spectrometry (GC-MS). FTIR indicated the existence of the different functional groups, XRD showed that the nanocomposite has the hexagonal wurtzite shape of ZnO nanoparticles, SEM-EDS showed a size of 50 nm, and elemental analysis depicts the existence of the different elements in the extract, which confirms, along with TGA results, the formation of DV-ZnO nanocomposite. The nanocomposite synergistic effect was examined for anticorrosion capabilities using gravimetric, electrochemical, and surface analysis methods. Both the plant extract and the nanocomposite exhibited corrosion inhibition abilities. However, the incorporation of the plant extract with ZnO increased the inhibition efficiency by 20 %. Weight loss and electrochemical methods concluded an inhibition efficiency of 80 % for DV-ZnO nanocomposite. The inhibition of the nanocomposite is due to the adsorption of the inhibitor on the carbon steel surface, which was verified using X-ray photoelectron spectroscopy and scanning electron microscopy (SEM). The adsorption was found to follow both Langmuir and Temkin isotherms. Surface examination using atomic force microscopy (AFM) found that the carbon steel surface roughness was decreased from the sample submerged in an uninhibited medium (Sa = 121.20 nm) when adding DV-ZnO nanocomposite (Sa = 22.95 nm) and DV plant extract inhibitor (Sa = 54.73 nm). [ABSTRACT FROM AUTHOR]

In this study, we developed novel BiOBr/WO2.72 nanocomposites (abbreviated as BO/WO) and systematically investigated their photocatalytic degradation performance against the pesticide dichlorvos under visible light irradiation. The experimental results demonstrated that the BO/WO nanocomposites achieved an 85.4% degradation of dichlorvos within 80 min. In comparison, the BO alone achieved a degradation degree of 66.8%, and the WO achieved a degradation degree of 64.7%. Furthermore, the BO/WO nanocomposites retained 96% of their initial activity over five consecutive cycles, demonstrating exceptional stability. Advanced characterization techniques, such as high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) confirmed the composition and catalytic mechanism of the composite material. The findings indicated that the BO/WO nanocomposites, through their optimized Type-I heterojunction structure, achieved efficient separation and transport of photogenerated electron–hole pairs, significantly enhancing the degree of degradation of organophosphate pesticides. This research not only propels the development of high-performance photocatalytic materials, but also provides innovative strategies and a robust scientific foundation for mitigating global organophosphate pesticide pollution, underscoring its substantial potential for environmental remediation. [ABSTRACT FROM AUTHOR]

The present work reports the synthesis of cobalt ferrite and its nanohybrids with polythiophene (PTh) in the weight ratios of 10% and 20%. The ferrite and its nanohybrids were characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy coupled with elemental mapping (Fe-SEM) to confirm the morphology as well as the structure of the synthesized nanohybrids. The nanohybrids were tested for their photocatalytic activity upon modification of PTh against Alizarin Yellow (AY), Congo Red (CR) and Brilliant Blue (BB). Almost 100% degradation was achieved in 30 min using 50 mg of the photocatalyst. The effect of catalyst concentration and dye concentration was also investigated to explore optimum concentration of the photocatalyst required for rapid degradation of the dye. The generation of radicals responsible for degradation was analyzed by radical scavenging experiments and a probable mechanism of degradation was proposed. [ABSTRACT FROM AUTHOR]

The pure and Sn-doped SeO2 thin films on borosilicate glass substrates were synthesized using a spray pyrolysis method. X-ray diffraction analysis revealed that higher and appropriate Sn doping concentrations would induce the thin film to transform from amorphous to crystalline behavior as the 7 wt% Sn-doped SeO2 thin film had a polycrystalline hexagonal crystal structure. The Fourier transform infrared spectroscopy spectra show that high Sn doping concentrations in thin films exhibit the O–Sn–O bending and Sn–O stretching modes of SnO2, and the O = Se = O bond symmetric stretching vibration for all thin films. The high-resolution X-ray photoelectron spectroscopy measurement revealed the oxidation states of Se0, Se4+, and Se6+ for SeO2 and Sn4+ for SnO2. The photoluminescence spectra revealed the intense ultraviolet and blue emission peaks and the weak green emission peak. A maximum optical transmittance of ~ 90% in the visible region can be displayed for the pure SeO2 thin film and decreased with increasing Sn doping concentration as a window layer in solar cells and other optoelectronic devices. The energy band gap value for the pure SeO2 was evaluated as 3.08 eV and reduced to 2.97, 2.88, 2.86, and 2.79 eV for 1, 3, 5, and 7 wt% Sn: SeO2, respectively. The lowest sheet resistance value was found for 5 wt% Sn: SeO2, which is 286 GΩ/sq. Furthermore, the high figure of merit values of 9.46 × 10–2 Ω−1/12 and 8.86 × 10–2 Ω−1/12 were obtained for pure and 5 wt% Sn: SeO2 thin films, respectively. [ABSTRACT FROM AUTHOR]

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs). [ABSTRACT FROM AUTHOR]

This paper investigates the ferroelectric and structural properties of BiFeO3 thin films with four different RE2O3 (Nd2O3, Eu2O3, Ho2O3, and Er2O3) buffer layers fabricated on a SrRuO3/n+-Si substrate through spin-coating. To analyze the BiFeO3 films with RE2O3 buffer layers, various techniques, such as X-ray diffraction, secondary ion mass spectrometry, atomic force microscope, and X-ray photoelectron spectroscopy were employed to investigate the crystalline structures, depth profiles, surface topographies, and chemical compositions. It was found that the BiFeO3 film with RE2O3 buffer layers exhibited improved electrical properties such as leakage current, remnant polarization, and coercive field compared to the control BiFeO3 film without a buffer layer. Moreover, the Eu2O3 buffer layer exhibited the lowest leakage current of 2.05 × 10–6 A/cm2, the highest remnant polarization of 43.76 μC/cm2, and the smallest coercive field of 188 kV/cm among all the RE2O3 buffer layers. The outcome is likely to have been caused by the introduction of Eu3+ ion to the BiFeO3 film, which resulted in a reduction in surface roughness, a significant preferred orientation of (110), and an increased concentration of Fe3+ ion. Consequently, this inhibited the fluctuation of Fe3+ to Fe2+ ions and reduced the occurrence of oxygen vacancies. [ABSTRACT FROM AUTHOR]

Organic dual‐state emitters show high quantum yields of luminescence in both solution and the aggregated state. Alkyl side chains are frequently used to engineer solid‐state structures and prominent examples are naphthalimide‐functionalized cyanostilbene derivatives (NICS‐X), where H‐aggregation takes place for ethoxyl substitution (NICS‐E), while methoxyl and butoxyl substitution (NICS‐M and NICS‐B) lead to the quasi‐isolated Q‐type structure. While this takes place for powder samples, vacuum‐sublimed thin films are used, and it is shown by photoluminescence (PL) measurements that H‐aggregation takes place for all three NICS derivatives. In contrast, the energy‐level alignment of NICS‐X films on graphite exhibits disparities as shown by photoelectron spectroscopy: pronounced disorder in NICS‐B films leads to energy‐level bending, while the energy levels of NICS‐M and NICS‐E films remain flat. In such a way, it is demonstrated that side‐chain engineering of luminogens affects the short‐range order (responsible for the PL) and the long‐range order (responsible for the energy‐level alignment) in different ways. Furthermore, the importance of a substrate (thin films vs powder) on the solid‐state aggregation is highlighted. [ABSTRACT FROM AUTHOR]

Laser ablation synthesis in a liquid environment is a green and low-cost technique that allows the preparation of nanostructures. In the last few decades, transition metal oxide nanostructures have attracted a great deal of attention from the research community due to their diversified applications. Tungsten and molybdenum oxides have tunable bandgaps and localized surface plasmon resonance peaks in the near-infrared region in reduced form, making them promising candidates for optical sensing, optical transistors, photothermal therapy, and photocatalysis. In this work, tungsten and molybdenum oxide nanoparticles are prepared in deionized water using pure tungsten and molybdenum metal sheets. XRD results showed the formation of tungsten and molybdenum oxide. SEM images showed that particles are spherical and have different sizes. X-ray photoelectron spectroscopy results showed that the W+5 and Mo+5 oxidation states are present along with the W+6 and Mo+6 oxidation states, respectively, which indicate that the prepared WO3 and MoO3 oxides exist in reduced form. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of anodic oxygen evolution reaction (OER) is regarded as the main bottleneck for ineffective hydrogen production efficiency, limiting the industrial application of electrochemical water splitting. Substituting the OER by urea electrooxidation reaction (UOR) and simultaneously developing highly active and economical bifunctional electrocatalyst for UOR and hydrogen evolution reaction (HER) is a promising method to realize energy-saving hydrogen production and urea-rich wastewater abatement. Herein, self-supporting Ni-NiO film grown on Ti mesh (Ni-NiO/TM) was successfully prepared by a facile cathodic electrodeposition method with using nickel acetate as the only raw material. Electrodeposition process was optimized by modulating the electrodeposition time and potential. x-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and Raman characterization revealed the optimized Ni-NiO/TM was comprised of crystalline Ni and amorphous NiO and its morphology exhibited nanosphere structure, assembled by nanosheets. Ni-NiO/TM sample prepared under the potential of −1.5 V and deposition time of 10 min illustrated the lowest UOR potential of 1.34 V at 50 mA cm−2 and robust stability, superior to the recently reported literatures. Furthermore, the HER potential was only −0.235 V to drive the current density of 50 mA cm−2. The cell voltage of urea-assisted electrolysis for hydrogen production in Ni-NiO/TM||Ni-NiO/TM two-electrode system only required 1.56 V to deliver 50 mA cm−2, obviously lower than that (>1.72 V) for overall water splitting. This work demonstrated the potential of Ni-based material as bifunctional electrocatalyst for energy-saving H2 production by urea-rich wastewater electrolysis. [ABSTRACT FROM AUTHOR]

Acidic wastewater from mining activities contains a large amount of Sb(III). Biochar can provide with an economical and efficacious method for removing of Sb(III). However, highly efficient removal was still challenging under acidic environment. In this study, bamboo charcoal biochar and rice straw biochar were modified with glutaraldehyde and chitosan to examine their Sb(III) adsorption performances in terms of adsorption isotherms, adsorption kinetics and thermodynamics under different treatment conditions, i.e. biochar dosages, pH values, adsorption durations, coexisting substances and temperatures. Characterizations including Brunauer–Emmett–Teller surface area analysis, Fourier transform infrared spectrometry, scanning electron microscope coupled with energy dispersive X-ray spectrometry as well as X-ray photoelectron spectroscopy were employed to further reveal the mechanisms. Results showed that the modified bamboo biochar and modified rice straw biochar showed excellent Sb(III) adsorption efficiency of 94.29% and 93.36%, respectively, under strongly acidic environment. The maximum Sb(III) adsorption capacities of the modified bamboo biochar and modified rice straw biochar reached to 81.16 mg/g and 72.92 mg/g, respectively. Langmuir adsorption isotherm model and quasi-secondary kinetic model best described the adsorption processes. Thermodynamic studies showed that the adsorption of Sb(III) by modified biochar was a spontaneous, exothermic and irreversible process. It was proposed that electrostatic attraction, complexation with functional groups (e.g., C = O, -NH2, -OH), as well as oxidation of Sb(III) were involved in the adsorption processes. The modified biochar has greater removal capacity for Sb(III) than pristine one, suggesting its potential applications for the wastewater treatment. [ABSTRACT FROM AUTHOR]

Two series of lactone-terminated alkanethiol adsorbates with five- and six-membered lactone groups, γ-COCnSH and δ-COCnSH (n = 11, 12), were synthesized and employed to create nanoscale self-assembled monolayers (SAMs) on gold substrates to mimic the properties of commercially available poly(lactic-co-glycolic acid) (PLGA) and poly(glycolic acid) (PGA) surfaces. 1H and 13C nuclear magnetic resonance (NMR) were employed to characterize the adsorbate molecules. The thicknesses of the corresponding self-assembled monolayers (SAMs) were evaluated by ellipsometry. The conformational characteristics of the SAMs were analyzed using polarization modulation infrared reflection adsorption spectroscopy (PM-IRRAS), with a focus on the C-H antisymmetric stretching vibrations of the alkyl spacers. To evaluate the packing densities of the monolayers, X-ray photoelectron spectroscopy (XPS) measurements were performed. Separately, contact angle measurements provided insights into the wettability of the surfaces. Remarkably, the contact angle data across a broad range of probe liquids for the γ-COC11SH and γ-COC12SH SAMs were consistently similar to each other and to the contact angle values of the PLGA surface, rather than to PGA. This finding suggests that the lactone-terminated SAMs investigated in this study effectively mimic nanoscale polyester surfaces, enabling the exploration of interfacial properties of polyesters in the absence of swelling and/or surface reconstruction phenomena. [ABSTRACT FROM AUTHOR]

This study investigates nitrogen-doped carbon synthesis and electrochemical properties as electrode material for energy storage devices, an additional focus of the work is on the electrochemical exfoliation synthesis of nitrogen-doped carbon using various precursors and doping methods. The physical properties of the synthesized sample are characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The electrochemical properties of the N-doped carbons are studied using cyclic voltammetry and galvanostatic charge-discharge cycling. Finally, the work explores the potential application of the N-doped carbons as electrode material for energy storage devices, such as supercapacitors. The results show that N-doped carbons exhibit electrochemical performance superior to that of graphene oxide, with higher electrical capacitance. The results demonstrate the potential of N-doped carbons as high-performance electrode materials for electrochemical energy storage applications. This paper aims to explain the advantages of N-doping in carbon materials more precisely in graphene and the use of these materials in creating electrodes for application in supercapacitors and batteries. [ABSTRACT FROM AUTHOR]

In this paper, a new pyrazole derivative, namely, (2-(((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino)-5-nitrophenyl)(phenyl) methanone (2-DPM) was uniquely used as an inhibitor of corrosion for carbon steel (C-S) in acidic solution (1 M HCl). Numerous techniques include electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface morphology analysis (SEM), energy-dispersive X-ray spectrometry (EDX), atom force microscopy (AFM), angle of contact, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible analysis. Molecular dynamic simulations (MDs) and quantum chemical computations (DFT) were utilized to assess the 2-DPM ability. The results show that the inhibitor, acting in a mixed inhibitory mode, considerably reduces the incidence of C-S corrosion by protecting the metal surface with an effective protective layer. The chemically adsorbed novel pyrazole (2-DPM) molecule has an improved corrosion performance of nearly 96% at 303 K, which is supported by EIS and theoretical analyses. The Langmuir isotherm model was shown to regulate the adsorption of 2-DPM on the surface of C-S. Finally, there is a strong correlation between theoretical research and experimental findings. [ABSTRACT FROM AUTHOR]

Baicalin (Bn) is one of the flavonoids with various biological activities, and its accurate determination is of great significance to clinical medicine. The new "MOF-on-MOF" materials have a broad application prospect. ZIF-67 and MIL-101(Fe) are typical metal–organic frame (MOF) materials, which have the advantages of flexible structure, large specific surface area, large porosity, and adjustable pore size. In this paper, a disposable and sensitive Bn electrochemical sensor based on ZIF-67/MIL-101(Fe) composite modified carbon paper (CP) electrode was developed for the first time. The sensing nanomaterials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV) was used to evaluate the electrochemical behavior of Bn on different modified electrodes. The results showed that ZIF-67/MIL-101(Fe)/CP exhibited a well-defined redox peak compared with bare CP, ZIF-67/CP, and MIL-101(Fe)/CP, which was attributed to the synergistic effect of ZIF-67 and MIL-101(Fe). Under optimal conditions, the electrochemical sensor was able to quantify Bn in the ranges of 0.01 ~ 3 µM and 3 ~ 6 µM with a detection limit (LOD) as low as 0.009 µM (S/N = 3). In addition, the sensor was successfully used for the quantitative analysis of Bn in Dual yellow oral liquid with reliable results. [ABSTRACT FROM AUTHOR]

Cation-disordered rocksalt (DRX) oxides show promise as lithium-ion battery cathodes due to their high theoretical capacity derived from anionic redox. However, the challenges of poor anionic redox reversibility, causing oxygen loss and voltage hysteresis, lead to rapid capacity decay. This study employs a dual-functional urea treatment on Li1.2Ti0.4Mn0.4O2 DRX cathodes, generating oxygen vacancies in the subsurface and a protective carbon nitride layer on the surface through interface reactions. Characterization via X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy confirms these alterations. The presence of oxygen vacancies reduces the average Mn valence, increasing the capacity contributed by Mn and enhancing the reversibility of anionic oxygen redox, thus curbing oxygen loss. Additionally, the carbon nitride layer curtails the parasitic reaction between active oxygen species and the electrolyte. Urea-treated Li1.2Ti0.4Mn0.4O2 exhibits enhanced electrochemical performance, retaining a higher capacity (151 mAh⋅g−1, 80.3% of capacity retention) after 50 cycles compared to neat Li1.2Ti0.4Mn0.4O2 (117 mAh⋅g−1, 64.6% retention). Furthermore, the treatment improves lithium-ion diffusion and rate capability. This dual-functional urea approach presents a promising strategy for enhancing DRX cathode materials and advancing high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Nanododecahedral ZIF-67 crystals were successfully synthesized by a simple coprecipitation method at room temperature and constructed with graphene oxide (GO) and Nafion as an electrochemical sensing platform for Cu2+. The properties of the electrode and the modified materials were analysed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), square wave stripping voltammetry (SWSV), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The experimental results show that the ZIF-67/GO/Nafion/GCE sensor platform has a stronger adsorption effect on Cu2+. It has high sensitivity (101.29 μA·μM−1) and a low detection limit (7.55 nM) in the linear range of 0.01 to 1.0 μM, as well as long-term stability, good repeatability and selectivity. The recovery rate was between 95.7 and 102.7% for real water samples. The method can be used for the trace analysis of Cu2+, which is valuable for the detection of trace metal ions in real water samples. [ABSTRACT FROM AUTHOR]

In this study, a label-free electrochemical aptasensor for sensitive detection of aflatoxin B1 (AFB1) was created by using a glassy carbon electrode (GCE) with polyaniline-functionalized graphene oxide (GO-PANI) and gold nanoparticles (AuNPs). Various spectroscopic techniques such as UV–Vis spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Zeta potential, and Raman spectra were employed to analyze the morphology and composition of the GO-PANI-Au nanocomposite, confirming its successful preparation. This aptasensor could be used for the detection of AFB1 with a broad linear range of 0.0001 to 50 ng/mL and a low limit of detection (LOD) of 0.0377 pg/mL under the optimized conditions. Furthermore, the constructed aptasensor displayed remarkable selectivity, repeatability, and stability. To validate the practical usability of our aptasensor, we successfully tested it on millet and corn samples, yielding a satisfactory recovery rate of 98.87–106.10% for AFB1 detection. This outcome highlights the potential application of our methodology in real sample analysis. A highly efficient and sensitive electrochemical aptamer sensor was successfully developed using GO-PANI-AuNPs nanocomposites, and can be used for the detection of AFB1 with good selectivity, repeatability, and stability. [ABSTRACT FROM AUTHOR]

GaN, a third-generation semiconductor, has gained widespread attention owing to its high temperature resistance, wide bandgap, and high critical breakdown electric fields. Magnetron sputtering has a broad potential in the field of low-cost growth of GaN on account of high efficiency, superior quality, and convenient operation. However, challenges caused from the pure Ga targets with a huge refrigeration system need to be resolved for wide practices. Here, a new and cost-effective Ga target for magnetron sputtering was fabricated by utilizing the wetting properties of CuGa2 and Ga. Mixed microcrystalline and amorphous GaN films were obtained via reactive magnetron sputtering employing the Ga target. The average deposition rate is about 1.68 nm/min, and the average roughness is ∼7.45 ± 0.26 nm under 100 W of sputtering power. In addition, the sputtered GaN films were found to be wide-bandgap and p-type semiconductors with high transmittance, as revealed by x-ray photoelectron spectroscopy and absorption spectra. The GaN films display a bandgap of ∼3.60 eV and a transmittance exceeding 88.5% in the visible range. Furthermore, field-effect transistors and metal–semiconductor–metal photodetectors have been fabricated using the obtained GaN films, demonstrating favorable response characteristics. The prospects of microcrystalline/amorphous GaN films in sensing, power devices, and flexible electronics were forecasted. Overall, a low-cost and pervasive route of target fabrication process expands the possibilities of using low melting point metals in magnetron sputtering. [ABSTRACT FROM AUTHOR]

This study investigates the cytotoxicity profile of superparamagnetic Fe3O4-Ag decorated nanoparticles against human fibroblasts (HFF-1) and breast cancer cells (MCF-7). The nanoparticles underwent comprehensive characterization employing scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and magnetic assays including hysteresis curves and zero-field-cooled (ZFC) plots. The nanoparticles exhibited superparamagnetic behavior as evidenced by magnetic studies. Cytotoxicity assays demonstrated that both HFF-1 and MCF-7 cells maintained nearly 100% viability upon nanoparticle exposure, underscoring the outstanding biocompatibility of Fe3O4/Ag decorated nanoparticles and suggesting their potential utility in biomedical applications such as drug delivery and magnetic targeting. Furthermore, the study analyzed the cytotoxic effects of Fe3O4 and Fe3O4-Ag decorated nanoparticles to evaluate their biocompatibility for further therapeutic efficacy. Results showed that neither type of nanoparticle significantly reduced cell viability in HFF-1 fibroblasts, indicating non-cytotoxicity at the tested concentrations. Similarly, MCF-7 breast cancer cells did not exhibit a significant change in viability when exposed to different nanoparticle concentrations, highlighting the compatibility of these nanoparticles with both healthy and cancerous cells. Additionally, the production of reactive oxygen species (ROS) by cells exposed to the nanoparticles was examined to guarantee their biosafety for further therapeutic potential. Higher concentrations (50–100 μg/mL) of Fe3O4-Ag nanoparticles decreased ROS production in both HFF-1 and MCF-7 cells, while Fe3O4 nanoparticles were more effective in generating ROS. This differential response suggests that Fe3O4-Ag nanoparticles might modulate oxidative stress more effectively, thus beneficial for future anticancer strategies due to cancer cells' susceptibility to ROS-induced damage. These findings contribute to understanding nanoparticle interactions with cellular oxidative mechanisms, which are crucial for developing safe and effective nanoparticle-based therapies. This investigation advances our understanding of nanostructured materials in biological settings and highlights their promising prospects in biomedicine. [ABSTRACT FROM AUTHOR]

The KSF-clay is a material that presents a high density of acidic active sites, ideal for being a heterogeneous acid catalyst with outstanding activity. For this study, KSF-clay was characterized by X-ray photoelectron spectroscopy and temperature-programmed desorption of ammonia. Additionally, studies of the adsorption of ethanol, propan-2-ol, and acetic acid molecules over KSF-clay surface to establish their thermal stability species were studied by diffuse reflectance infrared Fourier transform spectroscopy. The relationship between the properties of KSF-clay and the adsorption-interaction process with organic molecules is related to its performance as an acid catalyst. [ABSTRACT FROM AUTHOR]

This work aims at developing a customized ammoxidation catalyst through optimizing the metal oxide content in CrVO4/SiO2 catalysts. Various amounts of Cr–V–O with 1:1 molar ratio of Cr/V were successfully loaded on SiO2 via spray-drying method with colloidal silica as the binder. Polarized light microscope illustrated that the CrVO4/SiO2 particles presented as well dispersed microspheres in the microsize (20–80 μm). X-ray diffraction spectra confirmed the formation of monoclinic CrVO4 phase wherein the metal oxide content was ranged from 30 to 70 weight percent. FT-IR spectra indicated that the introduction of metal oxide had no obvious effects on the skeletal structure of SiO2. X-ray photoelectron spectroscopy analysis revealed that the valence state of V and Cr was hardly affected with increasing the metal oxide content. Performances of the obtained CrVO4/SiO2 catalysts with different metal oxide contents were investigated via the ammoxidation of a model compound, namely para-chlorotoluene (PCT) to para-chlorobenzonitrile (PCBN). A maximum conversion of 99.6% of PCT and 86.5% yield and 86.8% selectivity to PCBN have been obtained over the CrVO4/SiO2 catalyst with 60% weight of metal oxides at a temperature of 410 °C, n(PCT):n(NH3):n(air) = 1:3:15 and reaction load = 0.13 g/gCat·h. In addition, this catalyst was efficient and selective toward ammoxidation reactions of toluene, ortho- and meta-chlorotoluenes. [ABSTRACT FROM AUTHOR]

Biochar has proven effective in the remediation of excess nitrogen from soil and water. Excess nitrogen from agricultural fields ends up in aquatic systems and leads to reduced water quality and the proliferation of invasive species. This study aimed to assess the efficiency of chemically surface-modified biochar produced from invasive Pistia stratiotes L. for the adsorption of inorganic nitrogen (NH4+ and NO3−). Biochar structure was investigated using scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and inductively coupled plasma mass spectrometry. The results from adsorption experiments indicate that NH4+ removal was optimal (0.8–1.3 mg N g−1) at near-neutral pH levels (6.0–7.5), while NO3− removal was optimal (0.4–0.8 mg N g−1) under acidic pH conditions (4.8–6.5) using the modified biochar. These findings highlight the significance of solution pH, biochar morphology, and surface chemistry in influencing the adsorption of NH4+ and NO3−. However, further studies are necessary to assess the potential oxidative transformation of NH4+ to NO3− by biochar, which might have contributed to the reduction in NH4+ in the aqueous phase. [ABSTRACT FROM AUTHOR]

This study investigated the migration patterns of oxygen in the deoxidation process of Ti-48Al alloy scrap using electromagnetic levitation (EML) technology. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were employed to analyze the oxygen distribution patterns and migration path during EML. The refining process resulted in three types of oxygen migration: (1) escape from the lattice and evaporation in the form of AlO, Al2O; (2) formation of metal oxides and remaining in the alloy melt; (3) attachment to the quartz tube wall in the form of metal oxides such as Al2O3 and Cr2O3. The oxygen content of the scrap was dropped with a deoxidation ratio of 62%. It indicated that EML can greatly promote the migration and removal of oxygen elements in Ti-Al alloy scrap. [ABSTRACT FROM AUTHOR]

Ultrasmall nanoparticles (diameter 2 nm) of silver, platinum, and bimetallic nanoparticles (molar ratio of Ag:Pt 0:100; 20:80; 50:50; 70:30; 100:0), stabilized by the thiolated ligand glutathione, were prepared and characterized by transmission electron microscopy, differential centrifugal sedimentation, X-ray photoelectron spectroscopy, small-angle X-ray scattering, X-ray powder diffraction, and NMR spectroscopy in aqueous dispersion. Gold nanoparticles of the same size were prepared as control. The particles were fluorescently labeled by conjugation of the dye AlexaFluor-647 via copper-catalyzed azide-alkyne cycloaddition after converting amine groups of glutathione into azide groups. All nanoparticles were well taken up by HeLa cells. The cytotoxicity was assessed with an MTT test on HeLa cells and minimal inhibitory concentration (MIC) tests on the bacteria Escherichia coli and Staphylococcus xylosus. Notably, bimetallic AgPt nanoparticles had a higher cytotoxicity against cells and bacteria than monometallic silver nanoparticles or a physical mixture of silver and platinum nanoparticles. However, the measured release of silver ions from monometallic and bimetallic silver nanoparticles in water was very low despite the ultrasmall size and the associated high specific surface area. This is probably due to the surface protection by a dense layer of thiolated ligand glutathione. Thus, the enhanced cytotoxicity of bimetallic AgPt nanoparticles is caused by the biological environment in cell culture media, together with a polarization of silver by platinum. [ABSTRACT FROM AUTHOR]

The hydroxyapatite and copper-doped hydroxyapatite coatings (Ca10−xCux(PO4)6(OH)2; xCu = 0, 0.03; HAp and 3CuHAp) were obtained by the vacuum deposition technique. Then, both coatings were analyzed by the X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and water contact angle techniques. Information regarding the in vitro antibacterial activity and biological evaluation were obtained. The XRD studies confirmed that the obtained thin films consist of a single phase associated with hydroxyapatite (HAp). The obtained 2D and 3D SEM images did not show cracks or other types of surface defects. The FTIR studies' results proved the presence of vibrational bands characteristic of the hydroxyapatite structure in the studied coating. Moreover, information regarding the HAp and 3CuHAp surface wettability was obtained by water contact angle measurements. The biocompatibility of the HAp and 3CuHAp coatings was evaluated using the HeLa and MG63 cell lines. The cytotoxicity evaluation of the coatings was performed by assessing the cell viability through the MTT assay after incubation with the HAp and 3CuHAp coatings for 24, 48, and 72 h. The results proved that the 3CuHAp coatings exhibited good biocompatible activity for all the tested intervals. The ability of Pseudomonas aeruginosa 27853 ATCC (P. aeruginosa) cells to adhere to and develop on the surface of the HAp and 3CuHAp coatings was investigated using AFM studies. The AFM studies revealed that the 3CuHAp coatings inhibited the formation of P. aeruginosa biofilms. The AFM data indicated that P. aeruginosa's attachment and development on the 3CuHAp coatings were significantly inhibited within the first 24 h. Both the 2D and 3D topographies showed a rapid decrease in attached bacterial cells over time, with a significant reduction observed after 72 h of exposure. Our studies suggest that 3CuHAp coatings could be suitable candidates for biomedical uses such as the development of new antimicrobial agents. [ABSTRACT FROM AUTHOR]

Amorphous ZrO2 thin films with increasing Mg content were deposited on quartz substrates, by dip coating method. The films are transparent in the visible domain and absorbent in UV, with an optical band gap that decreases with the increase of Mg content, from 5.42 eV to 4.12 eV. The temperature dependent conductivity measurements showed typical semiconductor comportment. The decrease of the electrical conductivity by Mg doping was related to the increase of the OH groups (37% to 63%) as seen from X-ray Photoelectron Spectroscopy. It was found out that the electrical conductivity obeys the Meyer-Neldel rule. This rule, previously reported for different disordered material systems is obtained for ZrO2 for the first time in the literature. Exploring novel aspects of Mg-doped ZrO2, the present study underscores the origin of the Meyer-Neldel rule explained by the small-polaron hopping model in the non-adiabatic hopping regime. Determination of the presence of such a conduction mechanism in the samples hold promise for comprehending the important aspects, which might be a concern in developing various devices based on Mg-doped ZrO2. [ABSTRACT FROM AUTHOR]

This study explores the effects of various temperatures on the surface modification of carbon fibers, as well as the effect of differing voltages and currents on the morphology, deposition rate, and thickness of the Ni plating layers. Post-treatment characterization of the samples was conducted utilizing scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) methods, thus facilitating a discussion on the mechanism of Ni plating. The findings demonstrate that at a temperature of 500 °C, the carbon fiber surface exhibits the highest concentration of functional groups, including hydroxyl (-OH), carboxyl (-COOH), and carbonyl (-C=O), resulting in the most efficacious modification. Specifically, exceeding 500 °C leads to significant carbon fiber mass loss, compromising the reinforcement effect. Under a stable voltage of 7.5 V, the Ni-plated layer on the carbon fibers appear smooth, fine, uniform, and complete. Conversely, at a voltage of 15 V, the instantaneous high voltage induces the continuous growth of Ni2+ ions along a singular deposition point, forming a spherical Ni-plated layer. In addition, a current of 0.6 A yields a comparatively uniform and dense carbon fiber coating. Nickel-plated layers on a carbon fiber surface with different morphologies have certain innovative significance for the structural design of composite reinforcements. [ABSTRACT FROM AUTHOR]

Green nanoparticles are synthesized using environmentally friendly methods, and natural materials hold significant importance. This makes the process environmentally sustainable and reduces the production of harmful waste by-products. Green nanoparticles exhibit reduced toxicity which is crucial for biomedical applications. The current study suggested that yttrium nanoparticles (YNPs) should be synthesized, characterized, and evaluated for their diverse biological applications due to the rise in antibacterial resistance. The YNPs were prepared using a pine needle leaf extract (PNLE). The structural and morphological features have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), and vibrating sample magnetometry (VSM). The XRD pattern demonstrated the presence of yttrium oxide and yttrium nitrate phases. The crystallite size and particle size of the synthesized YNPs measured 1.696 nm and 24.55 nm, respectively. The XPS peaks showed two components with binding energies at 530.940 eV and 532.18 eV due to the bond between O–Y and OH–Y, respectively. Additionally, the ferromagnetic nature of the YNPs was confirmed by VSM analysis. The YNPs were tested for antibacterial activity on six uropathogenic bacteria (S. aureus, S. haemolyticus, E. faecalis, E. coli, K. pneumonia, and P. aeruginosa) using the microdilution assays, to find the minimum inhibitory concentration (MIC) as well as the minimum bactericidal concentration (MBC), the agar well diffusion assay, and antibiofilm screening assays, where they showed bacteriostatic action against all isolates (0.5–1 mg/mL MIC) and significant inhibition of biofilm formation (80% inhibition rate). The antioxidant capacity assessed by 1,1, diphenyl-2-picrylhydrazyl (DPPH) radical scavenging revealed 50% DPPH scavenging. Moreover, docking studies exhibited that YNPs inhibit crucial bacterial enzymes, including DNA gyrase, penicillin-binding proteins, carbapenemase, LasR-binding protein, and dihydropteroate synthase. These findings may explain the mechanisms responsible for the observed antibacterial effects of YNPs. Overall, these findings underscore YNPs as promising candidates for antioxidant and antibacterial applications. [ABSTRACT FROM AUTHOR]

Water may easily become polluted by pharmaceutical wastes, such as phenazopyridine hydrochloride. The pollutant can be removed by electrochemical oxidation in the form of minerals. A novel electrode has been developed for this purpose. Pt nanoparticles (PtNPs) are electrodeposited onto multiwalled carbon nanotubes supported onto fluorine-doped tin oxide (FTO/Glass). The resulting PtNP@MWCNT-FTO-E electrode is characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy, electron diffraction spectroscopy and X-ray photoelectron spectroscopy. The electrode exhibits high efficiency in the electrochemical oxidation process thanks to the large specific surface area of the PtNPs and their ability to behave as charge transfer catalysts. The contaminant undergoes complete mineralization, leaving no organics after treatment. The resulting nitrate ions further confirm contaminant mineralization, but fortunately, they disappear over time, which confirms the safety of the process in water treatment. Moreover, the electrode operates under a variety of applied potentials, pH values, temperatures and contaminant concentrations. The electrode exhibits high stability upon recovery and reuse while retaining its physical characteristics before and after use. This study highlights the benefit of using Pt nanoparticles in the electro-degradation of aqueous organic contaminants, especially waste pharmaceuticals, for the first time. It also recommends scaling up the process and studying the continuous-flow reaction process to assess the economic and technical feasibility in future large-scale applications. [ABSTRACT FROM AUTHOR]

Graphene was synthesized through a two-step pyrolysis method using waste candlenut (Aleurites moluccanus) shells as the precursor. Cerium (Ce)/graphene composites were prepared via an impregnation technique. The resulting graphene and Ce/graphene were characterized using various analytical methods, including Scanning Electron Microscopy with Energy-Dispersive Spectroscopy (SEM-EDS), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), Thermo Gravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) spectroscopy, Cyclic Voltammetry (CV), and Linear Sweep Voltammetry (LSV). The bio-carbon produced predominantly exhibited a graphene structure with flat carbon morphology and an interlayer distance of 0.33 nm. This structural information is supported by XRD data, which shows a broad and weak peak at 2θ = 26° corresponding to the C (002) plane, indicative of graphene presence. FTIR, XPS, and Raman spectroscopy further confirmed the presence of graphene through the detection of Csp2 aromatic bonds and the characteristic D, G, and 2D peaks. Notably, the performance of cerium can be enhanced by the incorporation of graphene, attributed to the large surface area and chemical interactions between Ce and graphene. Consequently, candlenut-derived graphene shows potential as a supportive material for modifying the properties of cerium, due to the current value of Ce/Graphene increase with presence of graphene, thereby opening avenues for various advanced applications, such as sustainable and high-performance energy storage systems. [ABSTRACT FROM AUTHOR]

The structural, surface, and upconversion (UC) luminescence properties of Y2O3:Ho3+,Yb3+ films grown by pulsed laser deposition, for different numbers of laser pulses, were studied. The crystallinity, surface, and UC luminescence properties of the thin films were found to be highly dependent on the number of laser pulses. The X-ray powder diffraction analysis revealed that Y2O3:Ho3+,Yb3+ films were formed in a cubic structure phase with an Ia 3 ¯ space group. The thicknesses of the films were estimated by using cross-sectional scanning electron microscopy, depth profiles using X-ray photoelectron spectroscopy (XPS), and the Swanepoel method. The high-resolution XPS was used to determine the chemical composition and oxidation states of the prepared films. The UC emissions were observed at 538, 550, 666, and 756 nm, assigned to the 5F4 → 5I8, 5S2 → 5I8, 5F5 → 5I8, and 5S2 → 5I7 transitions of the Ho3+ ions. The power dependence measurements confirmed the involvement of a two-photon process in the UC process. The color purity estimated from the Commission International de I'Eclairage coordinates confirmed strong green UC emission. The results suggested that the Y2O3:Ho3+,Yb3+ UC transparent films are good candidates for various applications, including solar cell applications. [ABSTRACT FROM AUTHOR]

Docetaxel (Doc), as a first-line chemotherapy drug for prostate cancer (PC), often loses its therapeutic efficacy due to acquired resistance and lack of targeting specificity. Therefore, there is a need to develop a novel drug that can overcome Doc resistance and enhance its targeting ability to inhibit PC progression. In this study, we prepared Au/Doc/Quer@PDA/A10-3.2 nanoparticles (NPs) composite drug by encapsulating Doc and quercetin (Quer) within polydopamine (PDA)-coated Au NPs and further modifying them with RNA oligonucleotide aptamer A10-3.2. A10-3.2 was used for specific targeting of prostate-specific membrane antigen (PSMA)-positive PC cells (LNCaP). Quer was employed to reverse the resistance of Doc-resistant cell line (LNCaP/R) to Doc. Physical characterization using ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful preparation of Au/Doc/Quer@PDA/A10-3.2 NPs. Fluorescence imaging and flow cytometry experiments demonstrated the targeting ability of Au/Doc/Quer@PDA/A10-3.2 NPs towards PSMA-positive LNCaP/R cells. Cell proliferation, apoptosis, invasion, and migration experiments revealed that Quer reversed the resistance of LNCaP/R cells to Doc. Immunoblotting experiments further confirmed the mechanism behind sensitization of chemotherapy by Quer. Finally, we evaluated the therapeutic efficacy of Au/Doc/Quer@PDA/A10-3.2 NPs in a mouse model of PC. In conclusion, this study synthesized and validated a novel nano-composite drug (Au/Doc/Quer@PDA/A10-3.2 NPs) for combating Doc-resistant PC, which could potentially be applied in clinical treatment of PC. [ABSTRACT FROM AUTHOR]

This work investigated the flocculation of sub-micron titanium dioxide (TiO2) by polyacrylic acids (PAAs), with a focus on studying the correlation between the PAAs adsorption conformation and the flocculation efficiency/floc property. The adsorption analysis of PAAs on the TiO2 surface was studied by attenuated total reflection Fourier transform infrared, Raman, X-ray photoelectron spectroscopy, CHNS elemental analyzer coupled with quartz crystal microbalance with dissipation monitoring. Adsorption densities were fitted using Langmuir and Freundlich isotherm models. The flocculation process of TiO2 by PAAs of different molecular weights (MWs) was monitored in real-time by a photometric dispersion analyser, and the floc structure was studied by scanning electron microscope. The results showed that the adsorption of PAAs followed the Langmuir isotherm, and formed monolayer adsorption on the TiO2 surface regardless of MWs through hydrogen and bidentate chelating chemical bonds. The thickness of adsorption layer increased with increasing MW, which could promote floc size by providing molecular "bridges"; but impeded the flocculation rate. For sub-micron particles, polyacrylic acid with a medium MW (512 kDa) was the optimum polymer owing to obtaining the fastest flocculation rate and relatively dense flocs in this work. PAA with high MW resulted in larger flocs with greater porosity, whereas the low MW PAA can only generate smaller flocs with a slower flocculation rate. [ABSTRACT FROM AUTHOR]

MoVN/MoNi4-MoO2 nanorods are synthesized using a two-step fabrication process consisting of the hydrothermal method and DC(V) and RF(Mo) magnetron co-sputtering technique. The resulting electrode exhibits a high surface area, that together with its intrinsic catalytic activity, achieves a synergistic effect, thereby improving the reaction kinetics of overall water splitting. The performance of the electrodes was tested in 1 M KOH solution, to understand the reaction mechanisms and catalytic efficiency of both the half-cell reactions (Hydrogen Evolution Reaction and Oxygen Evolution Reaction). The electrodes performed exceptionally well with overpotentials of only 14 mV and 244 mV at 10 mA cm−2 for HER and OER respectively compared to other electrode materials described previously in literature. Further, the stability of the electrodes was tested for 12 h showing a negligible change in current density for both HER and OER reactions. Overall electrolysis was performed for 12 h with the best electrode MoVN/MoNi4-MoO2 needing only 1.56 V to reach 10 mA cm−2. Material characterization using X-ray Diffraction, Scanning Electron Microscopy, and Transmission Electron Microscopy were carried out for crystal structure and morphological analysis. X-ray photoelectron spectroscopy was performed to understand the nature of the surface species of the best-performing electrode and to study the degradation effects after electrolysis. Hence, this work uncovers the outstanding properties of the MoVN/MoNi4-MoO2 electrode material with relatively high electrochemical surface area, low overpotential for both half-cell reactions (HER and OER), and negligible degradation which could provide a competitive path to the fabrication of low-cost and highly effective electrodes for application in commercial electrolyzers. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) sensing is crucial for environmental safety, necessitating the development of efficient NH3 sensors. In this study, an efficient NH3 sensor based on CdS quantum dots (QDs) decorated with ZnO (CdS/ZnO) covering optical fiber was successfully fabricated. The CdS/ZnO was first synthesized by a hydrothermal method, featuring an n-n heterojunction in the composite material. The optimal sensor with 10 wt% CdS QDs exhibits efficient performance, with a response sensitivity of 0.9 × 10−3 dB/ppm and R2 = 0.9858. Additionally, it demonstrates excellent selectivity and repeatability. Mechanistic insights for the NH3 sensor were elucidated through X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, and transmission electron microscopy. These results confirm that the enhancement in NH3 sensing performance is attributed to the formation of well-defined n-n heterojunctions. This study contributes to the advancement of gas-sensing technology, particularly in the detection of harmful gases, such as NH3. [ABSTRACT FROM AUTHOR]

Deposition-precipitation (DP) method is commonly used to prepare the supported metal catalysts. In this study, the modification effect of the mild DP method on the photocatalytic performance of TiO2 was investigated. The TiO2 samples with DP treatment, as well as Au/TiO2 prepared under the same conditions, showed enhanced photocatalytic performance of the degradation of methylene blue (MB). · OH generated by photoexcited holes is identified as the main intermediate reactive species during the degradation reaction. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) show that TiO2(A)-17 after DP treatment has the most amount of surface OH ad − species. The presence of surface OH ad − species not only changes the surface zeta potential, favoring the attraction of cationic MB; but also depresses the electron-hole recombination, favoring photodegradation of MB by hole-produced • OH. An implication of these findings is that the modification of support properties should be taken into account while preparing supported metal catalysts using DP methods. [ABSTRACT FROM AUTHOR]

Controlling tire local electronic structure of active ingredients to improve the adsorption-desorption characteristics of oxygen-containing intermediates over the electrochemical liquid-solid interfaces is a critical challenge in the field of oxygen reduction reaction (ORR) catalysis. Here, we offer a simple approach for modulating the electronic states of metal nanocrystals by bimetal co-doping into carbon-nitrogen substrate, allowing us to modulate the electronic structure of catalytic ao five centers. To test our strategy, we designed a typical bimetallic nanoparticle catalyst (FeCo NP/NC) to flexibly alter the reaction kinetics of ORR. Our results from synchrotron X- ray absorption spectroscopy and X-ray photoelectron spectroscopy showed that the co-doping of iron and cobalt could optimize the intrinsic charge distribution of Fe-Co NP/NC catalyst, promoting the oxygen reduction kinetics and ultimately achieving remarkable ORR activity. Consequently, the carefully designed Fe-Co NP/NC exhibits an ultra-high kinetic current density at the operating voltage (71.94 mA/cm2 at 0.80 V), and the half-wave potential achieves 0.915 V, which is obviously better than that of the corresponding controls including Fe NP/NC, Co NP/NC. Our findings provide a unique perspective for optimizing the electronic structure of active centers to achieve higher ORR catalytic activity and faster kinetics. [ABSTRACT FROM AUTHOR]

A series of morpholine salt volatile corrosion inhibitors (VCIs) were synthesized via solid-phase chemical reactions. The corrosion inhibition performance was assessed using evaporation weight loss, VCI capability, and corrosion weight loss tests. The corrosion inhibition mechanisms of the morpholine salt VCIs for carbon steel in atmospheric conditions were explored through electrochemical testing under thin film electrolytes, X-ray photoelectron spectroscopy (XPS), and computational simulations. Morpholine carbonate exhibited higher volatility. Corrosion weight loss tests showed an >85% reduction for steel treated with morpholine benzoate or morpholine carbonate. The inhibitors' inhibition mechanism, elucidated through X-ray photoelectron spectroscopy (XPS) and computational simulations, revealed that morpholine carbonate and benzoate form protective layers via physical and chemical adsorption on the steel surface, coordinating with iron atoms through nitrogen and oxygen atoms. Quantum chemical calculations demonstrated that morpholine carbonate had stronger adsorption energy and electron transfer capabilities, indicating superior corrosion inhibition performance over morpholine benzoate. [ABSTRACT FROM AUTHOR]

This study aims to study the formation quality of the film of dental silanes. Two dental silanes, 3-methacryloxyproyltrimethoxysilane (MPS) and 3-acryloyloxypropyltrimethoxysilane (ACPS), were deposited on the silica glass-equivalent model surface (i.e., n-type silicon(100) wafer) by varying the deposition time (5 h and 22 h). The film quality was then evaluated by ellipsometry, surface contact angle (CA) and surface free energy (SFE), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) in survey and high-resolution modes on Si2p, O1s and C1s. Ellipsometry confirmed that both silanes at the two different deposition times would produce 0.85–1.22 nm thick self-assembled monolayer on the silicon wafer surface. While the water CA of silanized surfaces (60.7–71.5°) was larger than the surface without silane (29.6°), the SFE values of all silanes (40.0–44.5 mN/m) were slightly less than that of the wafer surface (46.3 mN/m). AFM revealed that the MPS with 22 h silanization yielded a significantly higher roughness (0.597 μm) than other groups (0.254–0.297 μm). High-resolution XPS on C1s identified a prominent peak at 288.5 eV, which corresponds to methacrylate O-C*=O, i.e., the silane monolayer is extended fully in the vertical direction, while others are in defect states. This study proves that different dental silanes under various dipping times yield different chemical qualities of the film even if they look thin physically. [ABSTRACT FROM AUTHOR]

CrN and diamond-like carbon (DLC) coatings are deposited on the surface of 431 stainless steel by the direct current magnetron sputtering technique. The surface morphology, micro-structure, hardness, friction, and wear properties of CrN, CrN/DLC and multi-layer composite DLC coatings are investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, nanoindentation tester, scratch tester, and friction and wear tester. The results show that the surface of the single CrN coating is very rough for the columnar crystal structure with preferred orientation. When it serves as inner transition layers to form the composite DLC coatings, the surface gets much smoother, with reduced defects. The friction and wear results indicate that the composite DLC coatings exhibit lower coefficients of friction, and better wear and corrosion resistance in dry friction, deionized water, and seawater. In the dry wear and friction process, the single CrN coating is easily worn out, and severe friction oxidation and furrow wear both appear with a friction coefficient of 0.48. But the friction coefficient of a CrN coating in seawater is reduced to 0.16, and friction oxidation and wear loss are further reduced with water lubrication. The CrN/DLC coating has excellent tribological performance in three test concoctions and has the lowest friction coefficient of 0.08 in seawater, which is related to the higher sp3 bond content, density (1.907 g/cm3) and high degree of amorphization, contributing to high hardness and a self-lubrication effect. However, due to the limited thickness of CrN/DLC (1.14 µm), it easily peels off and fails during friction and wear in different testing conditions. In multi-layer composite DLC coatings, there are more sp2 bonds with decreased amorphization, high enough thickness (4.02 µm), and increased bonding strength for the formation of different carbides and nitrides of chromium as transition layers, which gives rise to the further decreased average friction coefficient and the lowest wear loss. Therefore, the CrN coating alone has good wear resistance, and, as with the inner transition layer with a DLC coating, it can effectively improve the overall thickness and the bonding strength of the multi-layer films by optimizing the chemical compounds of DLC coatings. These results provide experimental support and reference for the design and selection of surface coatings for 431 stainless steels in different working conditions. [ABSTRACT FROM AUTHOR]

This study examines the impact of varying oxygen flow rates on the properties of Cu2O thin films deposited via radio frequency (RF) magnetron sputtering. X-ray diffraction (XRD) analysis showed a phase transition from cubic Cu2O to a mixed Cu2O and CuO phase, eventually forming a Cu4O3 tetragonal structure as oxygen content increased. The surface morphology and cross-sectional structure of Cu2O thin films observed through field emission scanning electron microscopy (FE-SEM) were found to vary significantly depending on the oxygen flow rate. X-ray photoelectron spectroscopy (XPS) indicated notable variations in the chemical states of copper and oxygen. The Cu 2p spectra revealed peaks around 933 eV and 953 eV for all samples, with the S01 sample (deposited with only argon gas) exhibiting the lowest intensity. The S02 sample showed the highest peak intensity, which then gradually decreased from S03 to S06. The O 1s spectra followed a trend with peak intensity being highest in S02 and decreasing with further oxygen flow rates, indicating the formation of complex oxides such as Cu4O3. UV-Vis-NIR spectroscopy results demonstrated a decrease in transmittance and optical band gap energy with increasing oxygen content, suggesting a decline in crystallinity and an increase in defects and impurities. These findings underscore the critical role of precise oxygen flow rate control in tailoring the structural, morphological, compositional, and optical properties of Cu2O thin films for specific electronic and optical applications. [ABSTRACT FROM AUTHOR]

This study aims to establish and optimize a process for the fabrication of 3D microstructures of the biocompatible polymer Parylene C using hot embossing techniques. The different process parameters such as embossing temperature, embossing force, demolding temperature and speed, and the usage of a release agent were optimized, utilizing adhesive micropillars as a use case. To enhance compatibility with conventional semiconductor fabrication techniques, hot embossing of Parylene C was adapted from conventional stainless steel substrates to silicon chip platforms. Furthermore, this adaptation included an investigation of the effects of the hot embossing process on metal layers embedded in the Parylene C, ensuring compatibility with the ultra-thin Parylene printed circuit board (PCB) demonstrated previously. To evaluate the produced microstructures, a combination of characterization methods was employed, including light microscopy (LM) and scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). These methods provided comprehensive insights into the morphological, chemical, and structural properties of the embossed Parylene C. Considering the improved results compared to existing patterning techniques for Parylene C like plasma etching or laser ablation, the developed hot embossing approach yields a superior structural integrity, characterized by increased feature resolution and enhanced sidewall smoothness. These advancements render the method particularly suitable for diverse applications, including but not limited to, sensor optical components, adhesive interfaces for medical wearables, and microfluidic systems. [ABSTRACT FROM AUTHOR]

The evaluation of the photocatalytic properties of electrospun TiO2 nanofibres (TiO2-NFs) synthesised in the same experimental conditions using two distinct precursors, tetraisopropyl orthotitanate (TTIP) and tetrabutyl orthotitanate (TNBT), with morphology and crystalline structure controlled by annealing at 460 °C for 3 h is presented. The presence of circular-shaped TiO2-NFs was corroborated by scanning electron microscopy (SEM). By using X-ray photoelectron spectroscopy (XPS), the chemical binding energies and their interactions of the TiO2 with the different incorporated impurities were determined; the most intense photoelectronic transitions of Ti 2p3/2 (458.39 eV), O 1 s (529.65 eV) and C 1 s (284.51 eV) were detected for TTIP and slightly blue-shifted for TNBT. By using energy-dispersive X-ray spectroscopy (EDS), the chemical element percentages in TiO2 were determined. Using X-ray diffraction, it was found that the annealed electrospun TiO2-NFs presented the anatase crystalline phase and confirmed by Raman scattering. Bandgap energies were determined by diffuse reflectance spectroscopy at room temperature. The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide under exposure to ultraviolet light was studied using the TiO2-NFs obtained with the two molecular precursors. The results showed that the catalyst, prepared with the TTIP precursor, turned out to be the one that presented the highest photocatalytic activity with a half-life time (t1/2) of 28 min and a degradation percentage of 93%. The total organic carbon (TOC) in the solutions resulting from the 2,4-D degradation by the TiO2-NFs was measured, which showed a TOC removal of 50.67% for the TTIP sample and 36.14% for the TNBT sample. Finally, by using FTIR spectroscopy, the final chemical compounds of the degradation were identified as H2O and CO2. [ABSTRACT FROM AUTHOR]

As a most promising environmental technology, the substantial enhancement of photocatalytic efficiency is still a big challenge for practical applications. In this work, the surface of Bi2O2CO3 (BOC) nanotubes are modified by Cl and I. The as-obtained samples at different hydrothermal temperatures (T) are designated as T-X-BOC (X = Cl, I). X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS) prove that Cl and I merely chemically adsorb on the BOC surface, rather than dope into the crystal lattice. The surface modification of Cl and I slightly increases light absorption range, while significantly promotes the photoelectron migration from bulk to the surface that greatly enhances the carrier separation efficiency. Density functional theory (DFT) calculations further prove that surface Cl and I have adjusted band structure and surface charge distribution. Besides, the surface Cl and I favor the O2 adsorption and trap the surface photoelectrons, thus promoting the formation of •O2–; while the surface Cl and I impede the surface adsorption of H2O, thus refraining the generation of •OH. In the degradation of rhodamine B (RhB), holes and •O2− radicals play the crucial role. Under ultraviolet light irradiation (λ < 420 nm) for 45 min, the RhB degradation ratios over 150-Cl-BOC (94%) and 150-I-BOC (85%) are 4.2 and 3.7 times higher than that of original BOC (18%), respectively. This work demonstrates that the simple surface halogenation modification greatly improves the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Besides outstanding catalytic performance, the stability of nitrogen-doped carbon materials during storage is equally crucial for practical applications. Therefore, we conducted the first investigation into the stability of highly nitrogen-doped activated carbon (AC-NC-T) obtained by modifying activated carbon with CO2/NH3 in different storage media (air, vacuum and N2). The results of the catalysis of the oxygen reduction reaction and the activation of peroxymonosulfate for degrading bisphenol A by AC-NC-T show that the catalytic activity of AC-NC-T stored in air decays most prominently, while the performance attenuated only marginally when stored in vacuum and N2. The results from N2 adsorption isotherms, Raman spectroscopy, elemental and X-ray photoelectron spectroscopy indicate that the decline in catalytic activity is due to the presence of oxygen in the environment, causing a decrease in absolute contents of pyridinic N (N-6) and graphitic nitrogen (N-Q). After being stored in an air atmosphere for 28 days, the absolute contents of N-6 and N-Q in AC-NC-950 decreased by 19.3% and 12.1%, respectively. However, when stored in a vacuum or N2, the reduction in both was less than 7%. This study demonstrates that reducing oxygen concentration during storage is crucial for preserving high catalytic activity of nitrogen-containing carbon materials. [ABSTRACT FROM AUTHOR]

To address issues of global energy sustainability, it is essential to develop highly efficient bifunctional transition metal-based electrocatalysts to accelerate the kinetics of both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, the heterogeneous molybdenum and vanadium codoped cobalt carbonate nanosheets loaded on nickel foam (VMoCoCOx@NF) are fabricated by facile hydrothermal deposition. Firstly, the mole ratio of V/Mo/Co in the composite is optimized by response surface methodology (RSM). When the optimized composite serves as a bifunctional catalyst, the water-splitting current density achieves 10 mA cm−2 and 100 mA cm−2 at cell voltages of 1.54 V and 1.61 V in a 1.0 M KOH electrolyte with robust stability. Furthermore, characterization is carried out using field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) calculations reveal that the fabricated VMoCoCOx@NF catalyst synergistically decreases the Gibbs free energy of hydrogen and oxygen-containing intermediates, thus accelerating OER/HER catalytic kinetics. Benefiting from the concerted advantages of porous NF substrates and clustered VMoCoCOx nanosheets, the fabricated catalyst exhibits superior electrocatalytic performance. This work presents a novel approach to developing transition metal catalysts for overall water splitting. [ABSTRACT FROM AUTHOR]

Ultrafine KAl(OH)2CO3 dry powder (UDWP), as a novel high-temperature-resistant ultrafine dry powder fire extinguishing agent, has garnered significant attention in the field of aviation fire protection. However, its development has been hindered by its hydrophilicity, which leads to hygroscopicity, and its tendency for re-ignition due to oil deposition. Therefore, this study employs perfluorodecyltrimethoxysilane (PFDTMS) to modify the surface of UDWP, resulting in hydrophobic and oleophobic M-UDWP. The thermal stability and hydrophobicity of M-UDWP ensure its long-term stable storage in aircraft equipment compartments, thereby reducing aircraft maintenance costs. Additionally, its oleophobicity provides excellent anti-re-ignition performance, protecting aircraft power compartments from secondary fire damage. Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses indicate that the PFDTMS modifier was successfully grafted onto KAl(OH)2CO3. Furthermore, M-UDWP exhibits a three-stage thermal decomposition process. The first-stage decomposition can be regarded as a single-step reaction, and the calculated kinetic parameters provide accurate predictions. Thermogravimetric analysis-Fourier transform infrared spectroscopy-mass spectrometry (TG-FTIR-MS) results reveal that M-UDWP significantly produces H2O and CO2 during thermal decomposition, which is one of its core fire extinguishing mechanisms. For the combustion of #RP-3 and #RP-5 aviation kerosene, commonly found in aircraft engine nacelles, the extinguishing times required by M-UDWP are 243 ms and 224 ms, respectively, with minimum extinguishing concentrations (MEC) of 25.9 g/m3 and 23.4 g/m3, respectively. The study of M-UDWP's thermal stability aids in understanding its storage stability under high-temperature conditions and its fire extinguishing mechanisms in fire zones. Moreover, the research findings suggest that M-UDWP has the potential to replace Halon 1301 in aircraft engine nacelles. [ABSTRACT FROM AUTHOR]